We wouldn’t presume to know how up you are on islands in the Aegean Sea, but it’s probably safe to say you’ve heard more about Samos and Ikaria than the Fourni archipelago between them. But Fourni has something those bigger islands don’t: a ton of ancient shipwrecks.

That makes Fourni “an underwater archaeologist’s dream come true,” Philippe Cousteau says in this week’s episode of The Aquatic World. Last fall, a team of Greek and American archaeologists found 22 shipwrecks in just 17 square miles of the seafloor, and this June the same team found 23 more wrecks.

Some of the ships have been decaying on the seafloor for 2,500 years, Cousteau says, so little remains of the actual vessels. But they left behind their cargo of amphorae, clay jars that served as the ancient world’s shipping containers for things like olive oil, wine, and fish sauce.

Fourni’s waters harbor so many shipwrecks because it was an important navigational channel with a large volume of traffic in every time period, Peter Campbell, an archaeological director at the Albanian Center for Marine Research and one of the archaeologists on the expedition, tells Cousteau via video call. The wrecks date from as early as 525 B.C. to as recent as 1850.

After hearing from Campbell about how the vessels were fully loaded, Cousteau calls his crew to attention: “There must be more priceless tre-… antiquities around here somewhere.”